Document dDQXzYkNEN3BwwQQG7oKObKyB

418 INDUSTRIAL hygiene and occupational medicine Animal Experiments in the Study of the Biological Action of Dusts. A. Policard, Rev. med. miniere, 1949, no. 8, (Oct.-Nov.-Dec.), p. 7. Policard particularly discusses the design and value of animal experiments. The design of experiments involves the choice of animal (the rat appears to be the most suitable) as well as the selection of the dust in which the two essential criteria are the freshness of the material and its particle size. The dust may be introduced by inhalation in a dusting cabinet or by intratracheal or laryngeal injection of physiological solutions in which the dust is suspended. The reaction of connective tissue may be studied after subcutaneous, intramuscular or intra- peritoneal injection of the dust. The general effect on cells and on tissue make it possible to distinguish between one type and another. At present, the chief obstacle to progress in physio- pathological research in this field lies in our inadequate knowledge concerning the way in which fibrous tissue forms. Adaptation of English Summary. Delayed Pneumoconiosis. E. Martin, Rev. med. miniere, 1949, no. 8, (Oct.-Nov.-Dec.), p. 25. Martin describes six subjects with delayed pneumoconiosis who were followed over a long period and whose case histories are illustrated with numerous films. Pneumoconiosis with delayed evolution may develop either immediately or many years after the cessation of dust exposure. The disease develops slowly. The part played in its genesis by silica appears to have been exaggerated. It appears to be related to early tuberculous infection. Adaptation of English Summary. Chronic Retarded Pneumopathies of Beryllium. Anon., Rev. tuberc. 13:832, 1949. The pulmonary embarrassment provoked by the inhalation of beryllium dust or powder is of two types: the immediate and transitory pulmonary effects often associated with cutaneous and ocular manifestations, and the chronic, retarded pneumopathies. The results of personal observations of the latter type are described and a review of 36 cases by Hardy presented. The usual clinical symptoms are emaciation, fatigue, coughing, and dyspnea; the troubles are due more to the beryllium itself than to the silicates and fluorides present with the beryllium. The evolu tion of the pulmonary nodular development is traced through the reticular, micronodular and nodular stages. Some medical legal aspects of beryllium poisoning are also discussed. Adapted from Nuclear Sc; Abst. Endarteritis Obliterans in Worker Exposed to Lead. F. M. Troisi, Med. lavoro 41:197 (June-July) 1950. Troisi reports a case of endarteritis obliterans in a worker exposed to lead, who had worked for 22 years in the foundry of a printing establishment. Gangrene developed in the fifth right toe and required amputation of the toe. A few days later, vascular disorders and pain arose in the fifth left toe. These did not progress and healed in few months. Treatment included rest, foot contrast-baths, drinking about 2 qt. (2 1.) of milk daily, and pharmacological therapy. After recovery the worker changed to an occupation that did not involve lead exposure. No relapses have occurred during the 2)4 years that have elapsed since then. Results of Twelve Years' Investigation of Rock Miners in the Westphalian Coal Field. 0. Zorn, Beitr. Silikose-Forsch., 1949, no. 2, p. 1. Blood Changes in SrLicosis and Silicotuberculosis. A. Weisinger, Beitr. Silikose-Forsch., 1949, no. 2, p. 21. In a study of the erythrocyte sedimentation rate among 2,213 silicotics it was found that it it not possible to establish the existence of active-silicotuberculosis purely on that basis. Among persons with moderately advanced silicosis a significantly high rate can be explained by changes in protein equilibrium linked with the destruction of pulmonary tissue. Condensed from Bull. doc. med. inst. hyg. mines.